Method for protecting a computer system from side-channel attacks

Abstract

A method for protecting a computer system from side-channel attacks when using an encryption or decryption method for data packets of a data stream, wherein interruptions in the encryption or decryption method are generated by a random generator, where further computing operations are applied during the interruptions to already encrypted or decrypted data packets of the data stream or to data packets of the data stream which are yet to be encrypted or decrypted to generate random noise in the power consumption of the computer system.

What is claimed is: 
     
         1 . A method for protecting a computer system from side-channel attacks when using an encryption or decryption method for data packets of a data stream, the method comprising:
 generating interruptions in the encryption or decryption method via a random generator; and   applying further computing operations to already encrypted or decrypted data packets of the data stream or to data packets of the data stream which are yet to be encrypted or decrypted during the generated interruptions to generate random noise in power consumption of the computer system.   
     
     
         2 . The method as claimed in  claim 1 , wherein the further computing operations are part of an error-correction method. 
     
     
         3 . The method as claimed in  claim 1 , wherein the further computing operations are part of an algorithm for message authentication via a message authentication code. 
     
     
         4 . The method as claimed in  claim 2 , wherein the further computing operations are part of an algorithm for message authentication via a message authentication code. 
     
     
         5 . The method as claimed in  claim 1 , wherein, in cases of encryption, the data stream is initially subjected to the encryption method and then subjected to the further computing operations. 
     
     
         6 . The method as claimed in  claim 2 , wherein, in cases of encryption, the data stream is initially subjected to the encryption method and then subjected to the further computing operations. 
     
     
         7 . The method as claimed in  claim 3 , wherein, in cases of encryption, the data stream is initially subjected to the encryption method and then subjected to the further computing operations. 
     
     
         8 . The method as claimed in  claim 5 , wherein the further computing operations comprise an error-correction method. 
     
     
         9 . The method as claimed in  claim 1 , wherein, in cases of decryption, the data stream is subjected initially subjected to the further computing operations and then subjected to the decryption method. 
     
     
         10 . The method as claimed in  claim 2 , wherein, in cases of decryption, the data stream is subjected initially subjected to the further computing operations and then subjected to the decryption method. 
     
     
         11 . The method as claimed in  claim 3 , wherein, in cases of decryption, the data stream is subjected initially subjected to the further computing operations and then subjected to the decryption method. 
     
     
         12 . The method as claimed in  claim 5 , wherein the further computing operations comprise an error-correction method. 
     
     
         13 . The method as claimed in one of  claim 1 , wherein a start and finish of the further computing operations are controlled by the encryption or decryption method. 
     
     
         14 . The method as claimed in  claim 1 , wherein, if the further computing operations are finished, but the encryption or decryption method is unfinished, the interruptions generated by the encryption or decryption method are filled with computing operations based on random data. 
     
     
         15 . The method as claimed in  claim 2 , wherein an error-correction method is performed with random data which are generated by the random generator. 
     
     
         16 . The method as claimed in  claim 14 , wherein an error-correction method is performed with random data which are generated by the random generator. 
     
     
         17 . A computer system, comprising:
 at least one encryption or decryption unit;   a further computing unit arranged in series with the at least one encryption or decryption unit with respect to a data stream; and   a random generator configured to generate interruptions in an encryption or decryption method in the encryption or decryption unit;   wherein the encryption or decryption unit is operatively connected to the further computing unit such that, during the interruptions, the further computing unit applies further computing operations to already encrypted or decrypted data packets of the data stream or to data packets of the data stream which are yet to be encrypted or decrypted.   
     
     
         18 . The computer system as claimed in  claim 17 , wherein the random generator is operatively connected to the further computing unit such that, in an event that the further computing operations are completed, but the encryption or decryption method is not yet finished, the interruptions generated by the encryption or decryption method are filled with computing operations of the further computing unit based on random data from the random generator. 
     
     
         19 . The computer system as claimed in  claim 17 , wherein the computer system comprises a field-programmable gate array and the encryption or decryption unit and further computing unit are formed as a soft core or hard core. 
     
     
         20 . A non-transitory computer program product encoded with a program which is directly loadable into a computing unit of a computer system which, when executed by the computing unit, provides protection of the computer system from side-channel attacks when using an encryption or decryption method for data packets of a data stream, the computer program comprising:
 program code generating interruptions in the encryption or decryption method via a random generator; and   program code for applying further computing operations to already encrypted or decrypted data packets of the data stream or to data packets of the data stream which are yet to be encrypted or decrypted during the generated interruptions to generate random noise in power consumption of the computer system.